Why won't my drop down list populate from the array?

Question

I am using the following array. 
var actDesc = new Array(" ",
"Desc1 ",
"Desc2 ",
"Desc3 ");
// Array of HUD Activity Numbers.
var actNum = new Array(null,
"1 ",
"2 ",
"3 ");
// This populates the Description Drop-down List and works just fine.
function populateActDesc(dropdownField)
      var i;
      for (i=0; i < actDesc.length; i++)
         dropdownField.addItem(actDesc[i]);
//This is supposed to populate the Description Number Drop-down List but doesn't work.
function populateActNum(dropdownField)
      var i;
      for (i=0; i < actNum.length; i++)
         dropdownField.addItem(actNum[i]);
// Populates another field based on the Description Field value chosen and works as intended.
function getDesc(hudActivityDescription, hudActivityNumberField)
   var i;
   for (i = 0; i < actDesc.length; i++)                
      if (actDesc[i] == hudActivityDescription)        
        hudActivityNumberField.rawValue = actNum[i];        
   break;               
I placed the following into the drop-down list object holding the actDesc array (Event: initialize; Language: javascript):
actNoScript.populateActDesc(this);
This works just fine.
I placed the following into the drop-down list object holding the actNum array (Event: initialize; Language: javascript):
actNoScript.populateActNum(this);
This doesn't work.  Any ideas?
Any help would be greatly appreciated.  I am using LCD 8.2 ES on Vista 32bit.
Thanks,
Jerald

Answer 1

Hi Jerald,
You can't assign null to the display value of a drop down control.  If you change the HUD activity number array to remove the null it should work. 
That is;
// Array of HUD Activity Numbers.
var actNum = new Array("  ","1 ","2 ","3 ");
Bruce